- In idiopathic/heritable pulmonary arterial hypertension (PAH), indirect measures of exposure to traffic-related air pollution are associated with disease severity at baseline.
- Higher exposure to particulate matter ≤2.5 μm3 (PM2.5) is associated with poorer transplant-free survival.
Why this matters
- Exposure to traffic and air pollution is associated with increased mortality in numerous diseases, but its association with disease severity and outcomes in PAH remains unknown.
- 301 patients with PAH from the UK PAH national cohort study were evaluated for exposure to PM2.5, nitrogen dioxide (NO2) and indirect measures of traffic-related air pollution.
- Primary outcome: transplant-free survival.
- Association of air pollution markers with disease severity and European Society of Cardiology/European Respiratory Society risk (ERS/ESC) stratification were assessed.
- Funding: None disclosed.
- After adjustment for confounders, higher exposure to PM2.5 was associated with increased risk for death or lung transplant (HR, 4.38 per 3 μg/m3; P=.009).
- No significant associations were seen between recent exposure to PM2.5 at baseline catheterisation, NO2 or traffic-related pollution indicators and mortality.
- Indirect measures of exposure to traffic-related air pollution within the 500-1000 m buffer zones associated with the ERS/ESC risk categories and pulmonary haemodynamic severity at baseline.
- This association was strongest for pulmonary vascular resistance and 200 m increase in distance to road (relative change, 0.95; P=.001).
- Higher exposure to PM2.5 was associated with lower pulmonary vascular resistance, and no consistent association was found between pulmonary haemodynamics and NO2 exposure.
- Air pollution exposure estimated using the 2010 annual air pollution maps.